Operates on both 120 and 240V.Can be shipped to any country; you can find shipping costs by putting the item into the shopping cart; be sure to click "display rates"

No dangerous metal 240/120 volt lights.

Welcome to algae scrubbers. We are the only source for patented upflow scrubbers: U.S. Patent 9,115,008 and 9,708,207. All the oceans, reefs, lakes and rivers are naturally filtered only by algae, and all the organic particles remain in the water to feed the creatures. Reduce your glass cleaning and water changes, and create an environment for living micro-animals to grow inside the scrubber. No more dosing or possible overdosing. No more refilling. No more pale corals from low nutrients, and no more sick animals from high nutrients. Far more powerful than chaeto or refugiums, and does not remove the food particles. And you can use the algae as food!

Get the no-overflow advantage of an upflow scrubber: since it is ALL underwater, it can't overflow onto your floor. And now, all six of the magnets that go in the water are protected by a hard plastic cover inside of the black silicone; this prevents any scrapes or rust if you happen to accidentally let the magnets snap together.

This HOG3xx is a highest power 12-LED version of the original HOG3 which has 6 LEDs, and HOG3x which has 9 LEDs. This HOG3xx also has two power supplies like the HOG3x; one for a low-power 6-LED mode for startup when the growth surfaces are pure white, or for very new aquariums when there are not many nutrients in the water; and the second one to be added-in once growth darkens up the white surfaces.

This HOG3xx, just like the original HOG3 and HOG3x, offers much larger algae-attachment space to hold more growth between cleanings compared to the HOG.5, HOG1 or HOG1x, and is 2-sided instead of 1-sided because of the strings, compared to the HOG1.3 and HOG2 which have no strings. 2-sided allows light to reach further into the growth, and is best for saltwater (freshwater is best with no strings, such as on the HOG2). The strong magnets attach to thick aquarium walls up to 1/2" (13mm) glass or acrylic, which is a bit less than the original HOG3 can attach to because of the extra weight of the LEDs and power supply cords. Thus this HOG3xx is ideal for sumps of larger systems, because sumps rarely have thicknesses larger than 1/2" (13mm).

This HOG3xx scrubber has 36 square inches (225 square cm) of two-sided algal growth surface textures and strings, which once growing is designed to absorb the nutrients from this much feeding per day:

3 Frozen cubes, or

30 Pinches of flake, or

30 Square inches (180 square cm) of nori, or

8.4 grams of pellets

The number of gallons or liters of water in your tank or sump does not matter. If you feed more than the above amounts you can get multiple HOG3xx units, or a combination of HOG3xx and SURF units; multiple units are preferred over one larger unit because you can clean one unit per week, and because you'll always have one unit filtering while the other one starts growing again after a cleaning. Multiple units are also good for backup. The magnets attach the outside cover to the inside cover through the aquarium wall, and can be used on glass or acrylic 1/4 inch (6 mm) to 1/2 inch (13 mm). Not more. If your aquarium wall is 5/8 to 3/4" (18mm) it might work but you won't know until you try; it would be better to put the HOG3xx in your sump instead; it will work the same.

Compared to the HOG1.3 and HOG2 which look the same in size, the HOG3xx is meant for situations which have severe nutrient or algae problems, even in cases where the rocks in the display are covered in thick green hair algae. Algae-covered rocks are the most difficult situations to fix because the photosynthesis of that algae on the rocks is consuming nutrients from the water (often it measures zero), making it harder for the HOG filter to get the nutrients. To combat this you need stronger photosynthesis in your HOG scrubber, and that is what the HOG3xx is designed for. In particular, compared to the original HOG3 and HOG3xx, the extra extra LEDs of the HOG3xx provide the highest photosynthesis yet in this size scrubber and is suitable for the highest amount of nutrients (such as phosphate) in the water.

The large inside space of the HOG3xx growth compartment allows for lots of build up of algae, but most importantly the 12-LED light provides the strongest photosynthesis of all the HOGs, giving it the best chance of out-competing the scrubber on your rocks and also cutting through the phosphate in the water as high as 1.0 ppm. The 12 LED light grows green algae in situations where the lower power of the original HOG3, and certainly the HOG1.3 and HOG2, would only grow brown algae or slime. So this HOG3xx model is great for aquariums that have been running for years and are showing signs of old tank syndrome, or in highly-fed predator or NPS corals tanks, especially where the water has very high measurable phosphate. Be sure to follow the special instructions on reducing the light during start-up (by using the low-power mode) because the strong light and white surfaces will photo-inhibit initial growth in the scrubber if the light is not reduced.

The strings (ribbons) in the growth compartment of the HOG3xx are the same strings that are in the SURF2, SURF2x, SURF2xx, SURF4, SURF4x, SURF8 and SURF8x and are the heart of the ability of the scrubber to be able to use all the space for initial growth. The HOG1.3 and HOG2 have to grow outward from the textures before the open-area of the compartment is filled in (although they are great for freshwater); however the strings on the HOG3xx (like the original HOG3 and HOG3xx) allow this middle open area to start growing immediately, and do so using 2-sided growth (strings are 2-sided in growth) instead of the 1-sided growth of the textures alone. Thus the compartment fills much faster with growth, and this faster growth causes stronger photosynthesis (filtering).

The Green-Grabber (tm) algal growth surface is so rough and prickly that it might be the roughest thing you've ever felt. A cactus might be sharper, but that's about it. Rough surfaces are critical for allowing algae to attach and grow and thus provide strong absorption of nutrients. The rock-hard protrusions stick straight out 1 to 2 mm. Old style algae scrubber screens are made from "slippery" plastic canvas that is used for sewing and knitting; algae takes a long time to attach to it. Green-Grabber (tm) growth surfaces are not plastic at all; instead they are rock hard and have jagged rough edges and points (don't let children play with them). Green-Grabber surfaces are so good at grabbing algae and letting it grow that if you have high nutrients you may starting seeing tiny growth spots within hours instead of days. And the white color of the Green-Grabber surface reflects as much light as possible, for the most photosynthesis (filtering).

This is a hand-built Hang-On-Glass® (HOG) Upflow Algae Scrubber® (UAS) with strings and a Green-Grabbergrowth surface, for glass or acrylic 1/4 inch (6 mm) to 1/2 inch (13 mm) thick. This is the typical thickness range for small and some medium aquariums, and larger sumps, however you should measure yours to be sure. If your tank uses thin 1/8" (3mm) glass such as many low-cost 10 gallon aquariums do, this filter is not recommended because the magnets are strong enough that they might crack the glass. You would be better off getting a lower cost HOG.5 filter HERE

No electrical parts go inside the aquarium; only air. And the air bubbler is already supplied (it's sealed behind the growth surface), so you don't have to get an airstone. The bubbler is simply silicone air hose that has been cut lengthwise, and with cross-cuts, to form little flexible segments that are both adjustable and open-able to allow for easy cleaning. This HOG3xx will run on both 120V and 240V, and comes with a 10 ft (300 cm) power cord with a U.S. plug for each of the two power supplies. If you require a different plug you can get an adapter at any local hardware or travel store, or online, or you can cut off the U.S. plugs and install your own plugs from a hardware store. They are simple 2-prong plugs.

Comes with 3 ft (90 cm) of vinyl airline, but requires an air pump that can pump at least 2.0 liters per minute (.07 cfm), preferably more. A pump that says it can handle 2 or more airstones/outlets, or a pump with 2 tubing attachments instead of one, will be needed. You can have as much air as you like, however; 10 lpm pumps are no problem (although it will be louder). One powerful pump which works exceptionally well is the Whisper AP 300 from Tetra. You will need to combine the two outputs into one to feed the scrubber, using something such as the "Tee" or "Y" air line tubing fitting from Tom Aquatics. Make sure to put the air pump above the aquarium so that it will not drain any water if it shuts off, or use a one-way valve on the airline if the pump is lower.

Comes with 12 red (660 nm) 3-watt LEDs, which are attached to a heat sink inside the cover; the cover does get warm. The LEDs will give the aquarium or sump a slight red color at night when the aquarium lights are off. You will probably need to get a timer so you can run the LEDs for up to 22 hours per day (not 24), although you can start out at 24 hours as see how it grows. A single timer to handle both power supplies is fine. The LEDs never needs replacing.

The HOG3xx growth compartment will need to be cleaned every 7 to 14 days, by removing the inside cover, disconnecting the airline, and taking the inside cover to the sink so you can brush the algae off of the growth surface and the bubbler with a toothbrush, and also off of the strings. Sometimes though you can just reach in an grab the growth, especially in saltwater. The Green-Grabber growth surface is permanently glued to the inside cover using epoxy, however a few of the Green-Grabber particles may dislodge during the first few cleanings, which is normal. Cleaning the growth surface, bubbler, and the inside cover takes about a minute with a toothbrush.

This HOG3xx comes with a 1 year warranty: Warranty is for replacement or repair only; not a refund. Costs for shipping back to us are covered if you are in the U.S. Costs for shipping back to us are not covered if you are not in the U.S., however we will pay for shipping back to you. In either case, you will need to ship the entire unit back to us before we can ship a replacement. Warranty is limited to repair or replacement, and does not cover fish loss, personal injury, property loss, or direct, incidental or consequential damage arising from the use of it. The warranty and remedies set forth above are exclusive and in lieu of all others, whether oral or written, express or implied. We specifically disclaim any and all implied warranties, including but not limited to lost profits, downtime, goodwill, damage to or replacement of other equipment and property, and any costs of recovering animals, plants, tanks or other aquarium related items and/or equipment. We are not responsible for special, incidental, or consequential damages resulting from any breach of warranty, or replacement of equipment or property, or any costs of recovering or reproducing any equipment, animals or plants used or grown with this product.

Can be shipped to any country; you can find shipping costs by using the shopping cart; be sure to click "display rates". If you don't have a zip code, enter "zip code" instead. Note that shipping outside of the USA will probably require you to also pay an import charge when it arrives. We cannot mark it as "gift". The lowest cost (but slowest) foreign shipping is generally USPS Priority Mail International, but USPS Priority Express International is faster. The size of the shipping box is 12 x 10 x 6.5 inches (33 x 23 x 16 cm).

"This is just one week after my first [original HOG3] cleaning; Is growing super thick green algae"

..."And this is about 2 weeks growth, compartment completely full, nitrates are at 0, phosphates are between 0 and .25 per API, top layer was touching glass and was really yellow, when I pulled the layer off there was a ton of algae and it was dark green" -- Nathan P.

"It's been a little over a month since I installed two [original HOG3] filters on my 165g tank. Any algae that was growing on my rocks (just one spot) is now gone. Best part, so is any and all cyano!" -- 3Twinklets on the R2R site:

OK, this is more thick green growth then most people will get, but this customer's HOG3 or 3x or 3xx in saltwater is still fun to look at. This is mostly Ulva Fasciata, which looks like Easter basket filler; you can tell it's not Ulva Lactuca because there are no big "leaves", just thin strands...

This customer's HOG3 or 3x or 3xx in saltwater shows a combination of slime and green hair. The Green Grabber® strings have most of growth, and should be cleaned by scraping the strings with your fingers. The Green Grabber rock textures can be brushed in a sink, but don't brush the strings because your brush will get stuck in them. For freshwater, the HOG models without strings are best because freshwater only grows super slimey Spirogyro species, and must always be brushed in your sink because it's not thick enough to pull out by hand. So by not having strings, you don't have worry about your brush getting stuck in strings...

The 12 LED lights and 2 power cords of the HOG3xx

Customer's HOG3 or 3x or 3xx in saltwater, with very light colored growth. Just like vegetables, darker growth means more iron is in the growth, and other nutrients too; so you can add iron to the water (with supplement drops) or feed more seaweed like nori or algae pellets to the fish, which will also eventually get more iron into the water, and make darker growth. Also note that the filter does not have to be completely underwater; the top part can be above the waterline. This is also the way to block salt spray....

Here is a bunch of Cladophora algae (it grows in both fresh and saltwater) in a customer's HOG2 or 3 or 3x or 3xx. Since you can't see if strings are under the growth, you can't tell what model scrubber it is. Cladophora growth can get long, and unlike a waterfall style of scrubber, our upflow styles keep the long growth suspended in the water and inside the case. Waterfall style scrubbers by contrast will let the long growth flow straight down where it gets caught in your other filters and pumps. This is why waterfalls are not recommended for freshwater growth, which tends to grow even longer Spirogyra growth that gets a meter long: